Can hermit crab molt in water?

No, hermit crabs cannot molt in water. When a hermit crab is about to molt, it will retreat into its shell and close off the opening with a piece of debris. It will then absorb the water from its body and begin to shed its exoskeleton. The process of molting can take several days, and during this time the crab is very vulnerable to attack. If a hermit crab is submerged in water while it is molting, it will suffocate.